Global Joint Entropy Algorithm-Based Evaluation of Dexmedetomidine Combined Local Anesthetics in Brachial Plexus Block from Ultrasound Images

This paper aimed to explore dexmedetomidine combined local anesthetics in brachial plexus block through ultrasound imaging (UI) under global joint entropy algorithm. Patients who underwent upper limb surgery and brachial plexus block were selected as research objects. Patients in group A were given 0.375% ropivacaine and normal saline, and patients in group B were given 0.375% ropivacaine and 1.0 μg/kg dexmedetomidine. The results of UI were analyzed by global joint entropy-based K-means clustering (GKC) algorithm, and the use effects of the two methods were compared in combination with other postanesthesia manifestations. The results were as follows. The segmentation accuracy (96.21% and 83.52%) of GKC was higher than 82.21% and 70.52% of the local joint entropy-based K-means clustering (LKC) ( P < 0.05 ). The duration of sensory and motor block (352.78 ± 45.89 min and 324.38 ± 41.29 min) in group B was significantly longer than 292.28 ± 35.69 min and 256.58 ± 42.76 min in group A ( P < 0.05 ). Compared with 84.91 ± 8.77 beats/min and 89.58 ± 7.62 beats/min in group A, mean arterial pressure (70.24 ± 9.77 beats/min and 69.89 ± 8.97 beats/min) in group B was lower at T1 and T2 ( P < 0.05 ). The duration of postoperative pain (582.70 ± 51.89 min) in group B was longer than 372.89 ± 49.89 min in group A ( P < 0.05 ). The postoperative pain score (2.98 ± 1.08) in group B was significantly lower than 4.48 ± 2.19 in group A ( P < 0.05 ). Therefore, dexmedetomidine combined local anesthetics could prolong the duration of sensory and motor nerve block. Besides, dexmedetomidine had sedative and analgesic effects, so as to prolong postoperative pain time and reduce pain degree of patients.

A prospective randomised study of adjuvants for supraclavicular brachial plexus block: Clonidine vs Dexamethasone

Supraclavicular brachial plexus block is among foremost technique of regional anaesthesia administered during upper-limb surgery. Different adjuvants have been used with varied results for prolonging the sensory and motor blockade. Dexamethasone and Clonidine have been established as suitable adjuvants for blocks. Adding adjuvants to local anaesthetic drugs in nerve blocks has many benefits. We studied performance of dexamethasone or clonidine as additives to local anaesthetic in subclavian perivascular block as a part of upper limb surgery. Aim was to ascertain which of them is a better adjuvant. Study population was randomized to 2 groups of 50 patients each. Group 1 was given 5 ml of 2% lignocaine and 15 ml 0.5% bupivacaine with 8mg dexamethasone. Group 2 received 5ml 2% lignocaine and 15 ml 0.5% bupivacaine with 0.150 mg clonidine. Time to establishment of sensory & motor block, duration of analgesia and any adverse effects were observed. Statistical analysis was done with SPSS 13.0. Quantitative variables were assessed using student t test. Qualitative variables were analysed using Chi square test. P value &#60; 0.05 was defined as significant. Onset of sensory blockade was at 7.23+4.24 in group 1 and 8.36+2.68 minutes in Group 2. Average time to motor block was at 8.48+3.22 minutes in Group 1 and 9.58+3.71 minutes in Group 2. Analgesia’s duration in Group 1 and Group 2 was 998.2+338.5 and 879.3+284.5 minutes respectively. No major adverse events were seen in either group. Performance of dexamethasone was similar to clonidine as adjunct to local anaesthetic in subclavian perivascular approach of brachial plexus block. However, it has faster sensory and motor blockade’s onset. Analgesia’s duration observed was found to be longer, though the difference was statistically insignificant.

Optimal dose of perineural dexmedetomidine to prolong analgesia after brachial plexus blockade: a systematic review and Meta-analysis of 57 randomized clinical trials

Background and Objectives Peripheral injection of dexmedetomidine (DEX) has been widely used in regional anesthesia to prolong the duration of analgesia. However, the optimal perineural dose of DEX is still uncertain. It is important to elucidate this characteristic because DEX may cause dose-dependent complications. The aim of this meta-analysis was to determine the optimal dose of perineural DEX for prolonged analgesia after brachial plexus block (BPB) in adult patients undergoing upper limb surgery. Method A search strategy was created to identify suitable randomized clinical trials (RCTs) in Embase, PubMed and The Cochrane Library from inception date to Jan, 2021. All adult patients undergoing upper limb surgery under BPB were eligible. The RCTs comparing DEX as an adjuvant to local anesthetic (LA) with LA alone for BPB were included. The primary outcome was duration of analgesia for perineural DEX. Secondary outcomes included visual analog scale (VAS) in 12 and 24 h, consumption of analgesics in 24 h, and adverse events. Results Fifty-seven RCTs, including 3332 patients, were identified. The subgroup analyses and regression analyses revealed that perineural DEX dose of 30-50 μg is an appropriate dosage. With short−/intermediate-acting LAs, the mean difference (95% confidence interval [CI]) of analgesia duration with less than and more than 60 μg doses was 220.31 (153.13–287.48) minutes and 68.01 (36.37–99.66) minutes, respectively. With long-acting LAs, the mean differences (95% CI) with less than and more than 60 μg doses were 332.45 (288.43–376.48) minutes and 284.85 (220.31–349.39) minutes. Conclusion 30-50 μg DEX as adjuvant can provides a longer analgesic time compared to LA alone and it did not increase the risk of bradycardia and hypotension.

Dexmedetomidine-induced hemodynamic instability in patients undergoing orthopedic upper limb surgery under brachial plexus block: a retrospective study

Background Hemodynamic instability is a frequent adverse effect following administration of dexmedetomidine (DMED). In this study, we evaluated the incidence of DMED-induced hemodynamic instability and its predictive factors in clinical regional anesthesia practice. Methods One hundred sixteen patients who underwent orthopedic upper limb surgery under brachial plexus block with intravenous DMED administration were retrospectively identified. The primary outcome was the incidence of DMED-induced hemodynamic instability. The participants were allocated to a stable or unstable group by their hemodynamic instability status. Patients’ characteristics were compared between the groups. The relationship between the potential risk factors and development of DMED-induced hemodynamic instability was analyzed with a logistic regression model. Results DMED-induced hemodynamic instability was observed in 14.7% of patients (17/116). The unstable group had more women than the stable group (76.5% vs. 39.4%, P = 0.010). When patients were classified into four subgroup according to body mass index (underweight, normal weight, overweight, and obesity), there was significant difference in the composition of the subgroups in the two groups (P = 0.008). In univariate analysis, female sex, obesity, and pre-existing hypertension were significant predictors of DMED-induced hemodynamic instability. Multivariate analysis demonstrated that female sex (adjusted OR 3.86, CI 1.09; 13.59, P = 0.036) and obesity (adjusted OR 6.41, CI 1.22; 33.57, P = 0.028) were independent predictors of DMED-induced hemodynamic instability. Conclusions Female and obese patients are more likely to have hemodynamic instability following intravenous DMED administration in clinical regional anesthesia practice. This study suggests that DMED dose may be diminished to prevent hypotensive risk in these populations. Trial registration This article was retrospectively registered at WHO clinical trial registry platform (Trial number: KCT0005977).

768 Impact Of COVID-19 And BOAST Standards on Surgical Management of Upper Limb Injuries in A Large Teaching Hospital

Aim During the first peak of the COVID-19 pandemic, the BOA recommended that upper limb surgery for trauma should be avoided if possible, or performed as day-case if unavoidable, to reduce the risk of COVID-19 related negative outcomes. This audit assessed compliance with recommendations and impact on proportion of injuries managed conservatively due to COVID-19 risks, inpatient stay duration, COVID-19 infections, and corrective surgical intervention rates. Method Data was collected for all referrals to orthopaedics for upper limb fractures/dislocations at a large NHS teaching hospital in the North West over a 10-week period from April 4th to June 12th. Follow up was performed to 6 months after date of injury. Care was audited against the “British Orthopaedic Association Standard in Trauma: Management of patient with urgent orthopaedic conditions and trauma during the coronavirus pandemic”. Results A total of 112 patients were referred. 76% of patients were discharged from Emergency Department, with surgery indicated in 48%. Of those, 11% (n = 6) were not operated on due to COVID-19 risks and 1 patient from this group (16.7%) has required secondary corrective surgery. Surgery was completed as day-case procedure in 50%. COVID-19 swabs were not taken in 46% of referrals, 50% had a negative test and 4% positive. No patients tested positive after discharge following treatment. Conclusions Few cases were managed conservatively based on COVID-19 risk, and only 1 patient has required secondary surgery. More upper limb injuries may be managed conservatively, as per BOAST standards, with day-case procedures better utilised as an alternative.